1. Technical Field
This invention relates to an NC laser device which including combination of a numerical control device and a laser oscillator, and more particularly, to an NC laser device able to detect an abnormaly generated during a non-operative period thereof before machining is started.
2. Background Art
A gas laser oscillator using a CO.sub.2 gas laser and so forth provides a high output with a high efficiency and has excellent beam characteristics, and thus is widely used as an NC laser device combined with a numerical control device (CNC) for metal machining and so forth. In such an NC laser device, the alignment of a rear mirror, a return mirror and an output mirror is precisely adjusted, and careful attention is paid to vibration from outside and to temperature control of cooling water for optical parts during operation, to avoid any misalignment.
Nevertheless, misalignment can be caused by an unexpected mechanical impact during a non-operative period of the device, such as during transporting and so forth, and when such a misalignment occurs, the laser output is greatly reduced and the beam mode becomes poor. In practice, a reduced laser output can be corrected by a power correction function or the like, but it is not wise to continually use this function as the oscillation efficiency is lowered and remains in that state. Moreover, the deterioration of beam mode cannot be corrected, and this leads directly to a lowering of the machining performance.
Such an abnormality generated during a non-operative period cannot be detected until an operator examines the machined state after actual machining, and thus if an abnormal condition has occurred, the whole workpiece becomes useless and the machining efficiency is lowered.